Revert "Revert "Use native async/await support in pub.""

sdk/lib/_internal/pub_generated/test/transformer/runs_a_third_party_transform_on_the_application_package_test.dart

-// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS d.file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-library pub_tests;
-
-import '../descriptor.dart' as d;
-import '../test_pub.dart';
-import '../serve/utils.dart';
-
-main() {
-  initConfig();
-  withBarbackVersions("any", () {
-    integration("runs a third-party transform on the application package", () {
-      d.dir(
-          "foo",
-          [
-              d.libPubspec("foo", '1.0.0'),
-              d.dir("lib", [d.file("foo.dart", REWRITE_TRANSFORMER)])]).create();
-
-      d.dir(appPath, [d.pubspec({
-          "name": "myapp",
-          "dependencies": {
-            "foo": {
-              "path": "../foo"
-            }
-          },
-          "transformers": ["foo"]
-        }), d.dir("web", [d.file("foo.txt", "foo")])]).create();
-
-      createLockFile('myapp', sandbox: ['foo'], pkg: ['barback']);
-
-      pubServe();
-      requestShouldSucceed("foo.out", "foo.out");
-      endPubServe();
-    });
-  });
-}